The influence of degraded steering and suspension components on open-loop vehicle performance at the limits of tire-road frictional coupling is examined in this paper. The major conclusion obtained is that, with the exception of the shock absorber in certain maneuvers, the range of limit performance exhibited by new cars, as derived from design differences, is much larger than the in-use changes in limit performance of individual vehicles deriving from degradation of steering and suspension system components. This result should lead to future studies in which: 1.The influence of steering and suspension system degradation in the nonlimit regime of vehicle operation is examined. 2.Equipment for on-the-vehicle evaluation of suspension damping is investigated. 3.Greater emphasis is placed on the degradation of tires and brakes.